Photographic blixes and blixing

ABSTRACT

Photographic blix compositions containing (a) an ammonium or amine salt of the Fe , Co , or Cu complex with a polyfunctional ligand as the silver bleaching agent, (b) an amine or an ammonium thiosulfate and (c) a salt having as a cation an ammonium ion or a water-soluble amine with an ionizable proton attached to a nitrogen atom in the amine and as an anion a sulfite ion, bisulfite ion or a metabisulfite ion either with or without (d) an amine or ammonium salt of unchelated polyfunctional ligand are advantageously prepared in concentrated stock solutions or as dry mixtures to make working blix solutions that clear silver even in high concentrations along with residual silver halides from developed silver halide emulsion layers with substantially shorter clearing times than blixes outside the invention.

United States Patent P. 14,362 10/1956 Germany Primary Examiner-Norman G. Torchin Assistant Examiner-Mary F. Kelley Attorneys-William H. J. Kline, James R. Frederick and Ray Carter Livermore ABSTRACT: Photographic blix compositions containing (a) an ammonium or amine salt of the Fe'**, Co***, or Cu complex with a polyfunctional ligand as the silver bleaching agent, (b) an amine or an ammonium thiosulfate and (c) a salt having as a cation an ammonium ion or a water-soluble amine with an ionizable proton attached to a nitrogen atom in the amine and as an anion a sulfite ion, bisulfite ion or a metabisulfite ion either with or without (d) an amine or ammonium salt of unchelated polyfunctional ligand are advantageously prepared in concentrated stock solutions or as dry mixtures to make working blix solutions that clear silver even in high concentrations along with residual silver halides from developed silver halide emulsion layers with substantially shorter clearing times than blixes outside the invention.

PHOTOGRAPHIC BLIXES AND BLIXING This invention is related to chemical compositions for photographic processing and to blix compositions for use in photographic blixing of silver in developed photographic elements, and to blixing photographic elements.

In the usual processing of exposed silver-salt-sensitized multilayer multicolor-forming photographic elements, both silver and dye images are produced in the image layers by the photographic developing step or steps. The silver image and any residual silver halide in the developed photographic element are usually removed by converting the silver to a silver salt by a silver bleach solution followed by the conversion of the silver salt into a diffusible, water-soluble complex with a fixing bath and then subsequently washing the bleached and fixed photographic element to remove the silver salt complex, leaving the unobscured dye images. Blix (bleach-fix) baths are known which combine the bleaching and fixing steps into a single-process step. Known blix solutions used complexed iron III as the oxidant, usually as ethylenedinitrilotetraacetato ferrate (Ill) salts and various simple silver ligands, such as, thiosulfate or thiocyanate, alone or in combination. For example, German Pat. No. 866,605 describes a blix containing from 25 to 60 g./l. of sodium ethylenedinitrilotetraacetato ferrate (Ill), from to g./l. of an alkali metal or ammonium thiocyanate and from 75 to 200 g./l. of an alkali metal or ammonium thiocyanate. This blix solution and other known blix solutions do not have the desired blixing rates for the rapid processing of photographic elements now desired or, in some instances, required. Furthermore, known blix solutions are not practical for blixing photographic elements containing high concentrations of silver.

Farmer's reducer produced by mixing an alkali metal ferricyanide and an alkali metal thiosulfate is another known blix; however, because of its short life, it is not practical for the usual commercial processing applications.

Blix compositions are desired which are stable, are rapid acting and will be useful for removing silver from photographic elements containing high cohcentrations of silver.

It is, therefore, an object of our invention to provide novel blix compositions that are advantageously used for rapid removal of silver and silver salts from developed silver-saltsensitized photographic elements.

Another object is to provide a novel blix composition for removing silver from photographic elements that contain a high concentration of silver.

Another object is to provide a novel blix composition which has good keeping stability both at working concentrations, as well as at concentrated stock solution concentrations.

Another object is to provide novel concentrated stock solutions that are advantageously used for preparing blix solutions for photographic processing.

These and still other objects of our invention are accomplished by the preparation and use of our blix compositions.

The blix compositions ofour invention contain a. a bleaching agent for silver that is a salt of an unchelated cation such as ammonium ion or a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and has an anion that is a complex of a transition metal, such as, Fe***, Co***, Cu, etc., chelated by a polyfunctional ligand;

b. a thiosulfate fixing agent having as a cation an ammonium ion or a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine; and

c. a salt with either an ammonium ion or a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine as the cation and an anion that is a sulfite ion or provides a source of sulfite ions, such as bisulfite, metabisulfite, etc.

ln addition to components (a), (b) and (c) described above, our blix compositions advantageously also contain d. a salt with an ammonium ion or a water-soluble organic amine with an ionizable proton attached to a nitrogen atom in said amine as the cation and an uncomplexed polyfunctional ligand as the anion.

Our blix compositions are characterized by containing essentially no alkali metal ions. No alkali metal salts are used in our blix compositions. An ammonium ion or water-soluble organic amine having an ionizable proton attached to a nitrogen wherein T, T and T each represent the same or different member, such etc.), hydrogen, an alkyl group, especially an alkyl group having from one to six carbon atoms (e.g., methyl, ethyl, hydroxyethyl, propyl, hydroxypropyl, methoxyethyl, chloroethyl, fluoroethyl, butyl, amyl, hexyl, cyclohexyl, etc.), an aryl group, such as a phenyl group e.g. phenyl, tolyl, etc.), and together T and T supply the atoms required with the nitrogen atom (to which they are attached) to complete a heterocyclic ring having from five to six atoms in the ring, such as, a pyridine (e.g., pyridine, methyl pyridine, chloropyridine, etc. a morpholine (e.g., morpholine, methyl morpholine, chloromorpholine, etc.), a piperidine (e.g., piperidine, methylpiperidine, chloropiperidine, etc.), etc.

Typical amines used to form a cation for our salts include methyl amine, dimethyl amine, trimethyl amine, ethyl amine, diethyl amine, triethyl amine, hydroxyethyl amine, di(hydroxyethyl)amine, tri(hydroxyethyl)amine, propyl amine, butyl amine, amyl amine, hexyl amine, cyclohexyl, amine, aniline, m-toluidine, pyridine, methyl pyridine, chloropyridine, morpholine, methylmorpholine, chloromorpholine, piperidine, etc.

The components of our blix compositions are advantageously used over wide ranges of concentrations. For example, in the working blix solution (the solution used to contact the photographic elements in a tray, or processing machine) our bleaching agent (a) is advantageously used in the concentration range from about X 0.0] mole/liter to about l mole/liter with a preferred range of from about 0.1 mole/liter to about 0.6 mole/liter; our fixing agent (b) is advantageously used in the range of from about 0.01 mole/liter to about 5. moles/liter and preferably in the range of from about 0.1 mole/liter to about 2. moles/liter; our salt (c) used as a source of sulfite ions is advantageously used in the concentration range of from about 0.001 mole/liter to about 2. mole/liter, and preferably in the range of from 0.01 mole/liter to about 0.2 mole/liter. When an ammonium or amine salt of unchelated polyfunctional ligand (salt d) is used in our blix, it is usually used at up to about 0.1 the concentration of the chelated salt (a). Our working blix solutions are advantageously used over the pH range of from about 4 to about 9 and preferably in the range of from 6 to about 7.

The polyfunctional ligands used include those having the formulas:

an ammonium group, a water-soluble amine having an ionizable proton attached to a nitrogen atom in the amine, and

group, such as carboxy, a phosphono group (e.g.,

represented by the formula described previously (such that not more than one ofQ and represent an ammonium group or a water-soluble amine having an ionizable proton), an alkyl group (e.g., methyl, ethyl, propyl, butyl, cyclopentyl, cyclohexyl, etc., including an aralkyl group, e.g., benzyl, B-phenethyl, o-acetamidobenzyl, etc., and including a heterocyclylalkyl group (e.g., pyrrolidylmethyl, pyrrolidylbutyl, benzothiazolylmethyl, tetrahydroquinolylmethyl, me), an aryl group, such as, a phenyl group (e.g., phenyl, tolyl, 0-, p-carboxyphenyl, etc.), a napthyl group (e.g., a-naphthyl, B-naphthyl, etc.), and a heterocyclic group (e.g., pyridyl pyrrolyl, thiazolyl, oxazolyl, etc.); G, G, G and G each represent the same or different divalent group, such as, a divalent hydrocarbon residue, for example: an alkylene group (e.g., an ethylene group, a propylene group, a butylene group, etc., each of which is unsubstituted or substituted with groups, such as, hydroxyl, amino, nitro, halogen, a lower alkyl group, a lower alkoxy group, etc.), an arylene group e.g., a phenylene group, a naphthylene group, etc., each of which is unsubstituted or substituted with groups such as, hydroxyl, amino, nitro, halogen, a lower alkyl group, a lower alkoxy group, etc.) and a divalent heterocyclene group (e.g., a pyridylene group, a 4,5-oxazolylene group, a 4,5 thiazolylene group, etc.); X represents Boo a member, such as, oxygen, sulfur, a=PR group, a=C

represents a group, such as, a A,

group, a cyclohexylene group, a phenylene group, and a 1 I L a R R (CH M-IA R R R, R, R R, R", R R and R each represent a member, such as, hydrogen, hydroxyl, an amino group, nitro, halogen, a lower alkyl group (e.g., methyl, ethyl, butyl, etc.) and a lower alkoxy group (e.g., methoxy, ethoxy, butoxy, etc.) such that no single carbon atoms in the structure containing said groups R through R contains more than one hydroxyl group, more than one amino group and more than one nitro group; A- represents an integer of from 2 to 4; 11 represents an integer of from 1 to 4; and L represents a carboxy group or a phosphono group as described previously for L, L, L and L.

Our polyfunctional ligands are also advantageously described by the following formulas Ill and IV:

III R If 1' R L (i? C X)p] -C L 1L?" d-1 3 e-l R5 |-1 R7 2- sulfur,

11:]? B group a=0 Row group and a =NR group; R represents a lower alkyl group (e.g., methyl, ethyl, butyl, etc), an aryl group, such as a phenyl group (e.g., phenyl, tolyl, etc.), a naphthyl group (e.g., anaphthyl, B-naphthyl, etc); R and R each represent a member, such as, hydrogen, a lower alkyl group (e.g., methyl, ethyl, butyl, etc.) and a (OH L group; It represents an integer of from l to 2; L represents a carboxy group or a phosphono group (e.g., a P 0- (Q group); O and Q" each represent a member, such as, hydrogen, an ammonium group, a water-soluble amine having an ionizable proton attached to a nitrogen atom in said amine (such that not more than one of Q and Q represent an ammonium ion or a water-soluble amine with an ionizable proton), an alkyl group as described previously for Q and Q, an aryl group as described previously for Q and Q and a heterocyclic group as described for Q and Q; and formula IV:

wherein L and L are as defined previously for formula I, and L is as defined previously for formula III; L represents a car- PO- (Q group); O and 0 each represent a member, such as, hydrogen, an ammonium ion, a water-soluble amine having an ionizable proton attached to a nitrogen atom (such that not more than one of Q and Q represent an ammonium ion or a water-soluble amine with an ionizable proton), an alkyl group, an aryl group and a heterocyclic group, said alkyl, aryl and heterocyclic groups being as described previously for Q and Q; i, j, m and n each represent integers of from 2 to 4; Z is as defined previously for formula ll, excepting that L is further defined as a carboxy group or a phosphono group P 0-- group);

(e.g., a

Q and Q" each represent a member, such as, hydrogen, an ammonium ion, a water-soluble amine with an ionizable proton (such that not more than one of Q or Q represents an ammonium ion or a water-soluble amine with an ionizable proton), an alkyl group, an aryl group and a heterocyclic group, said alkyl, aryl and heterocyclic groups being as described previously for Q and Q.

Included among illustrative polyfunctional ligands used to advantage according to our invention are the following which illustrate those of formulas l and ill:

. Nitrilotriacetic acid Oxalic acid Malonic acid .Chloromalonic acid Ethylmalonic acid .Aminomalonic acid Bromomalonic acid Succinic acid 9. Glutamic acid Adipic acid Diglycolic acid Ethyliminodipropionic acid Ethylene di( thioglycolic) acid Thiodiglycolic acid Malic acid Tartaric acid OOQOMAUN- l7. Citric acid 18. Nitrilo-N,N,N-trimethylenephosphonic acid 19. o-Carboxyanilino-N,N-dimethylenephosphonic acid X 20. Propylamino-N,Ndimethlenephosphonic acid 21. 4-(N-pyrrolidino)butylamine-N,N-

bis(methylenephosphonic acid) 22. o-Acetamidobenzylamino-N,N-dimethylenephosphonic acid) 23. o-Toluidine-N,N-dimethylenephosphonic acid 24. Z-Pyridylamino-N', N-dimethylenephosphonic acid 25. Tetraethyl methylenediphosphonate 26. Tetraethyl octylidinediphosphonate 27. Octylidinephosphonic acid 28. Triammonium octylidine diphosphonate 29. Triammonium tridecylidenediphosphonate 30. TetrabutyLB, B-diethyl-B-methylethylidenediphosphonate 31. Diammonium cyclohexylemethylenediphosphonate 32. Tetraethyl benzylidenediphosphonate 33. Tetraphenyl o-phenylbenzylidenediphosphonate 34. Dodecylbenzylidenediphosphonic acid 35. Methylcarbonylbenzylidenediphosphonic acid 36. Tetraethyl nonadecylidenediphosphonate 37. Tetraethyl-l-pyrrolylidenediphosphonate 38. Methylene diphosphonic acid The following will illustrate typical examples of the polyamine polycarboxylic and polyamine polyphosphonic acid chelating agents represented by formulas II and IV:

. Ethylene diamine tetraacetic acid 2. do do do do, tetraammonium salt 3. Pentaacetic acid diethylene triamine 4. do do do do, pentaammonium salt 5. Ethylene diamine-N,N,N, N'-tetramethylenephosphonic acid 6. l,Z-Cyclohexanediamine-N,N,N, N'-

tetramethylenephosphonic acid 7. l,3-Diaminopropanol-N,N,N', N-

tetramethylenephosphonic acid 8. l,3-Propanediamine-N,N,N, N-

tetramethylenephosphonic acid l,6-Hexanediamine-N,N,N',N-

tetramethylenephosphonic acid Included among the bleaching agents of our invention are the following typical compounds:

I. Ammonium ethylenedinitrilotetraacetato ferrate (Ill) 2. Ammonium ethylenedinitrilotetraacetato cobaltate (III) 3. Hydroxyethylammonium ethylenedinitriloacetato ferrate (III) 4. Ammonium hydroxyethylethylenedinitriloacetato ferrate (III) 5. Tris(hydroxyethyl) ethylenedinitrilotetraacetato ferrate (Ill) 6. Ammonium ethylenedinitrilodiacetato dichloro cobaltate (III) 7. Ammonium ethylenedinitrilotetraacetato cuprate (II) 8. Ammonium ethylenedinitrilotetraphosphonate ferrate (III) ammonium Bleaching agent 9. Ammonium diethylenetrinitrilopentaacetato ferrate (III) 10. Ammonium nitrilotriacetato cuprate (II) I l. Ammonium l,2-cyclohexanediaminetetraacetato ferrate (Ill) X 12. Triammonium tris-(oxaloto)ferrate (III) 13.Tetraammonium bis-(hydrogen citrato) cuprate (II) 14. Ammonium hexamethylenedinitrilotetra (methylenephosphonate) ferrate (III) l5. Ammonium l,2-propylenediaminetetraacetato ferrate (III) In general, the silver bleaching agents of our invention are prepared by l reacting the appropriate metal salt, e.g., a ferric salt, cobaltous salt or cupric salt with an aqueous solution or slurry of a polyfunctional ligand, such as, is described by formulas I, II, III and IV, followed by (2) neutralization of residual acid group(s) with either ammonium hydroxide or an amine. The cobaltous complex is oxidized to the cobaltic complex. It is advantageous to elevate the temperature of the aqueous reaction mixture ofligand and appropriate metal salt to a temperature in the range from room temperature to about 95 C. Typical metal salts used to advantage include the following:

ferric sulfate ferric chloride ferric bromide ferric hydroxide cobaltous chloride cobaltous acetate cupric chloride cupric nitrate Bleaching Agent 1, i.e., ammonium ethylenedinitrilotetraacetato ferrate (III), for example, is advantageously prepared by adding fresh hydrated ferric hydroxide to a slurry of ethylenedinitrilotetraacetic acid and heating to a temperature of about to C. to form the ferric complex ofethylenedinitrilotetraacetic acid followed by neutralizing the acid complex with ammonium hydroxide. The acid complex is also advantageously prepared by slurrying fresh ferric hydroxide in hot water and adding powdered ethylenedinitrilotetraacetic acid. The precipitate of hydrated ferric hydroxide used in this reaction is advantageously prepared by reacting ferric nitrate hydrate with 9-H 0 in water with ammonium hydroxide. The precipitate is washed free of ammonium nitrate by decantation and centrifugation with water.

Bleaching Agent 2 is advantageously prepared by oxidizing diammonium ethylenedinitrilotetraacetato cobaltate (II) with hydrogen peroxide or other suitable oxidizing agent. The diammonium ethylenedinitrilotetraacetato cobaltate II is advantageously prepared by reacting cobaltous acetate in warm water with ethylenedinitrilotetraacetic acid followed by neutralization with ammonium hydroxide.

Representative Bleaching Agents, 2, 3, 4, 5, 6, 7, 8, 9, 10, ll, 12, l3, l4 and I5 are advantageously prepared by methods similar to those described for Agents 1 and 2, but using the polyfunctional ligand, transition metal salt, amine or ammonium hydroxide listed in the following Table I:

TABLE I Ammonium hydroxide.

o. llydroxycthylmnint.

Do. do Tri(hydroxcthyl) amine. Cobaltous chloride. Ammonium hydroxide. Cupn'c chloride D lotetraphosphonic ac Ferric cl1loridc.. Do. 9 Diethylenetrinitrilopentaacetic aeid do I10. 10... Nitn'lotriacetic acid Cupric cl1lo ridt D01 11 1,2-cyclohcxanediamine tetra acetic acid. Ferric chlondc Do. 12--. Ox ic aci o Do. 13 Citric acid Cupric chloridv. Do. 14 Hexamethylenedinitrilo tetra (methylenephosphonic) acid. Fcrnc chloride Do. 15 1,Z-propylcnedinitrilotetraacetic acid .do. Do.

The Co++ is oxidized to (30 after complex salt is prepared.

Bleaching agents made from other polyfunctional ligands and other amines according to our invention are advantageously prepared by procedures similar to those illustrated for Bleaching Agents 1 through 15.

A very important characteristic of our blix compositions is that they can be prepared ahead of use as concentrated stock solutions which have not been possible with compositions containing alkali metal salts of transition metal complexes of polyfunctional ligands. Sodium ethylenedinitrilotetraacetato ferrata III, for example, has a solubility of only about 90 g/liter (or about 0.24 mole/liter). This rather low solubility of sodium ethylenedinitrilotetraacetato ferrate Ill has made blix solutions containing it of very limited use in blixing color photographic elements and other elements having high concentrations of silver to be removed. Concentrated stock solutions containing parts of our blix compositions advantageously contain our ammonium or amine salt of a complex of Fe**", Co or Cu chelated by our polyfunctional ligands at concentrations of from about 0.3 mole/liter to about 2 moles/liter. The concentrated stock solution containing our bleaching agent also advantageously contains the ammonium or amine salt of unchelated ligand at concentrations of from about 0.05 mole/liter to about mole/liter and a sufficient amount of ammonium hydroxide or an amine to adjust the pH of this solution in the range of from about 6.5 to about 10. A second concentrated stock solution is advantageously made to contain other components required in the blix such as the ammonium thiosulfate or amine salt of H S O acid fixing agent and salt providing a source of sulfite ions, e.g., ammonium sulfite, ammonium bisulfite, ammonium metabisulfite, and the corresponding amine salts (of these anions). This concentrated stock solution advantageously contains the fixing agent in the concentration range of from about 3.0 moles/liter to about 8.6 moles/liter and enough of the salt (usually up to about 1 mole per liter) providing a source of sulfite ion to adjust the pH of this solution to a pH in the range offrom about 4 to about 7. The pHs of the two stock solutions are advantageously selected so that when they are combined with the necessary amount of water, a working blix solution is obtained having a pH in the range of from about 4 to 9 and preferably in the range from about 6 to about 7.

Our blix compositions also advantageously comprise dry mixtures of sufficient amounts of components, such as, our bleaching agent, our fixing agent and our salt providing a source of sulfite ions so that when the mixture is dissolved in water, the desired concentrated stock solution or working solution is obtained A liquid component, such as, an amine or ammonium hydroxide solution when needed in the blix is advantageously packaged separately for use in preparing either a concentrated stock solution or a working blix.

Our blix compositions are used advantageously in photographic processing wherever it is desired to remove silver and silver halide from an emulsion layer or layers as for example in any of the photographic elements designed for color photography, such as those containing color-forming couplers such as those described in Frohlich et al. US. Pat. No. 2,376,679; Vittum et al. U.S. Pat. No. 2,322,027; Fierke et al. U.S. Pat. No. 2,80l,l 71; Godowsky, U.S. Pat No. 2,698,794; Barr et al. U.S. Pat. No. 3,227,554 and Graham, U.S. Pat. No. 3,046,129; or elements to be developed in solutions containing color-forming couplers such as those described in Manners and Godowsky, U.S. Pat. No. 2,252,718; Carroll et al. U.S. Pat. No. 2,592,243; and Schwan, U.S. Pat. No. 2,950,970.

Any photographic silver halide emulsions are advantageously used in elements processed with our blixing compositions. These emulsions comprise silver chloride, silver bromide, silver bromoiodide silver chlorobromide or mixtures thereof. Coarse grain or fine grain emulsions prepared by any of the well-known procedures are usedv The emulsions advantageously contain any of the known chemical sensitizers, spectral sensitizers, antifoggants, stabilizers, coating aids and other addenda used in photographic elements. The silver halide emulsions advantageously contain any of the various hydrophilic colloids, such as, naturally occurring substances, e.g., proteins, for example, gelatin, gelatin derivatives, cellulose derivatives, polysaccharides such as dextron, gum arabic,

etc. and synthetic polymeric substances, such as, soluble polyvinyl compounds like poly(vinylpyrrolidone) acrylamide polymers, etc. Any of the known nondiffusible color-forming couplers known in the art are advantageously used in emulsions that contain incorporated couplers. The phenolic and naphtholic couplers are used as cyan-dye-formers; the 5- pyrazolone couplers are used as magneta-dye-formers and the open chain ketomethylene couplers are used as yellow-dyeformers. Any of the usual support materials used for photographic films and papers are advantageously used.

The photographic processes using our blix solutions use the aqueous alkaline developer solutions containing conventional developing agents, such as, hydroquinones, catechols, aminophenols, 3-pyrazolidones, phenylenediamines, ascorbic acid derivatives, etc., the primary aromatic amino developing agents being used advantageously for color development.

The following examples are included for a further understanding of our invention:

EXAMPLE 1 Blix A of our invention is made having the following composition:

Ammonium :thylenedinitrilotetraacetato Blix X, outside our invention, is made having the following composition:

Sodium ethylenedinirrilotetraucerato ferrate (ill) 0.] mole Sodium thiosulfute LO mole Sodium sulfite O.l mole water to l liter An exposed single layer gelatinous silver halide emulsion coating is developed in a conventional aqueous alkaline developer solution containing hydroquinone and p-methylamino-phenol sulfate as developing agents to produce about 200 mg. of developed silver/ft. of coating. One sample of this exposed and developed coating contacted with our Blix A is cleared of the silver in 35 seconds. Another sample of the same exposed and developed emulsion coating is contacted with Blix X outside our invention and is cleared of silver in seconds.

Similar advantages can be shown for other blix solutions like Blix A, but using in place of ammonium ethylenedinitrilotetraacetato ferrate lll other bleaching agents of our invention such as bleach compounds 2 through 15 compared with blixes outside our invention containing the sodium salt of the bleaching agent instead of our ammonium or amine salts of the bleaches.

EXAMPLE 2 Blixes A, B and C of our invention are made. Blix A has the composition of Blix A in example I. Blixes B and C contain 0.29 mole/l. and 0.56 mole/l. of ammonium ethylenedinitrilotetraacetato ferrate (Ill), respectively, and contain the same concentrations of ammonium thiosulfate and ammonium sulfite used in Blix A. An exposed and developed single layer gelatinous silver halide. emulsion coating is prepared as described in example 1. Separate samples of this coating are contacted with Blixes A, B and C and the clearing times are recorded in the following table:

Blix Clearing Time A 35 sec 8 25 sec C 22 sec.

The data in the above table indicate that an increase in the concentration of the bleach (oxidant) decreases the time required for bleaching the silver. We have found that a molar concentration of ethylenedinitrilotetraacetato ferrate (Ill) (either as the ammonium salt or any metal-salt) of 0.56 as shown in the above table is unattainable when one or both of the other two salts, i.e., the thiosulfate and the sulfite, are not present as the ammonium salts (or amine salts). Thus, only an all-ammonium ion and/or amine salt blix affords high oxidant concentration required for short blix times.

EXAMPLE 3 Blixes Y, A and E are made having the compositions shown below:

Blix Y (outside our invention) Blix E (of invention) Ammonium ehtylenedinitrilotetraacetato ferrate (lll) 0.4 M Ammonium thiosulfate 1.0 M Ammonium sulfite 0.1 M

A conventional multilayer color film containing three differently sensitized gelatino silver halide emulsion layers containing three different incorporated color-forming couplers is light-image exposed, then given negative development, reversal flash, color development as described by Column 1 1, lines 74 through line 36 in Column 12 of Carroll et al. U.S. Pat. No. 2,944,990, then given an aqueous acetic acid stop bath and then one portion of this film is treated with Blix Y, another portion with Blix A and another portion with Blix E. The 1,, time to clear the portions of film of silver as measured by infra red silver density are listed below:

Blix t in minutes through in place of ammonium ethylenedinitrilotetraacetato ferrate (Ill).

EXAMPLE 4 A gelatino silver halide emulsion is divided into three parts. In one portion (A) of the emulsion is incorporated a phenol cyan-dye-forming coupler, dissolved in a coupler solvent; in another portion (B) of the emulsion is incorporated a 5- pyrazolone magenta-dye-forming coupler, dissolved in a coupler solvent and, in another portion (C) of the emulsion is incorporated an open chain, yellow-dye-forming coupler. These emulsions are made and coated to give 100 mg. of coupler/ft", 200 mg. of silver/ftF, 500 mg. of gel/ft? The coatings are lightexposed and color-developed in an aqueous alkaline color developer solution containing N-ethyl-B-methanesulfonamidoethyl-3-methyl-4-aminoaniline sulfate as the developing agent, followed by an aqueous acid stop bath. The amount of silver in the coatings of portions A, B and C is measured before blixing, after seconds of blixing and after seconds of blixing. The following table gives the results:

EXAMPLE 5 A two-part blix composition is prepared as follows:

Part A An aqueous concentrated stock solution having a total volume ofabout 150 ml. is made containing about l g. of ammonium thiosulfate and about 11 g. of

ammonium metabisulfite.

Part B An aqueous concentrated stock solution having a total volume of about 150 ml. is made containing about 60 g. of ammonium ethylenedinitrilotetraacetato ferrate (Ill), about 6 g. of ethylenedinetrilotetraacetic acid tetraammonium salt, and about 23 g. of 28 percent ammonium hydroxide (in water). A working blix solution having a pH in the range from about 6.4 to about 6.8 is prepared by combining Part A, Part B and about 700 ml. of water. This blix working solution is used to blix light-image exposed multilayer, multicolor photographic paper elements (containing cyan-, yellowand magenta-colorforming couplers) after they have been color developed in aqueous alkali primary aromatic amino color developing agent solution, then given water washing. Our blix rapidly and effectively removes the developed silver image and residual silver halide, leaving a good color print reproduction of the light-image used for exposure.

Similar results are advantageously obtained when example 5 is repeated, substituting other bleaching agents of our invention, such as, Bleaching Agents 2 through 15 in place of Bleaching Agent 1.

Similar advantageous results are obtained when example 5 is repeated, using concentrations of ammonium ethylenedinitrilotetraacetato ferrate (lll) up to about g. in the ml. of Part B concentrate with corresponding increases in the amount of ethylenedinitrilotetra acetic acid tetraammmonium salt and an adjustment ofthe amount of ammonium hydroxide to adjust the pH of Part B in the desired range. Proportionately smaller amounts of Part B are used for a given amount of Part A (to produce a working blix solution ofa given concentration).

The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

We claim:

1. A photographic blix composition comprising:

a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe, Co, and Cu, chelated by a polyfunctional ligand;

b. a thiosulfate fixing agent having a cation selected from the class consisting of an ammonium ion and a watersoluble organic amine having an ionizable proton attached to a nitrogen atom in said amine;

c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions.

. A photographic blix composition comprising:

. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe**, Co" and Cu, chelated by a polyfunctional ligand selected from those having the formulas:

and

group, and a NR group; R represents a group selected from the class consisting of an alkyl group and an aryl group; R and R represent members selected from the class consisting of hydrogen, a lower alkyl group and a(Cl-l ),,,,---L group; h represents an integer of from 1 to 4; p represents an integer of from 1 to 2; and Z represents a group selected from the class consisting ofa i ('3 group, a phenylene group, a cyclohexylene group, and a R k group, a

1 1i I a 1'15 1'17 p;

R, RR R, R, R R and R each represent a member selected from the class consisting of hydrogen, hydroxyl, an amino group, nitro, halogen, a lower alkyl group and a lower alkoxy group such that no single carbon atom in the structure containing said groups R through R contains more than one hydroxyl group, more than one amino group and more than one nitro group; k represents an integer of from 2 to 4; h

represents an integer of from 1 to 4; and L represents a member selected from the class consisting of carboxy and a phosphono group;

b. a fixing agent having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine;

c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions.

3. A photographic blix composition comprising:

a, a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe***, Co and Cu, chelated by a polyfunctional ligand selected from those having the formulas:

consisting of hydrogen, an ammonium group, a water-soluble organic amine having an ionizable proton attached to a consisting ofa carboxy group and a nitrogen atom in said amine, an alkyl group, an aryl group and hydroxyl group, more than one amino group and more than one nitro group; d, e, fand g each represent integers of from I to 4; p represents an integer of from l to 2; X represents a member selected from the class consisting of oxygen, sulfur, a

PR group, a =O group, and a =NR group; R represents a group selected from the class consisting of an alkyl group and an aryl group; R and R represent members selected from the class consisting of hydrogen, a lower alkyl group, and a(CH ),,,,L group; It represents an integer of from i to 4; L represents a radical selected from the class consisting of a carboxy group (Q 7 group; O and Q each represent members selected from the class consisting of hydrogen, an ammonium group, a watersoluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, an alkyl group, an aryl group and a heterocyclic group; and formula:

and a i, j, m and n each represent integers of from 2 to 4; Z represents a group selected from the class consisting ofa and a group, a phenylene group, a cyclohexylene group and a R, R, R R, R, R R, R and h are as described previously; k represents an integer of from 2 to 4; and L represents a group selected from the class consisting of a carboxy group and a group; O and Q each represent members selected from the class consisting of hydrogen, an ammonium ion, a water-soluble organic amine having an ionizable proton on a nitrogen atom, an alkyl group, an aryl group and a heterocyclic group;

b. a fixing agent having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine;

c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions.

wherein L and l.. each represent a carboxy group; R, R, R

R", R R R and R each represent a member selected from the class consisting of hydrogen, hydroxyl, an amino group,

nitro, halogen, a lower alkyl group and a lower alkoxy group such that no single carbon atom in the chain contains more than one hydroxyl group, more than one amino group and more than one nitro group; d, e,fand g each represent integers of from 1 to 4; p represents an integer of from 1 to 2; X

represents a member selected from the class consisting of ox- Ron ygen, sulfur, a= PR group, a=C

group, and a: NR group; R represents a group selected from the class consisting of an alkyl group and an aryl group; R and R represent members selected from the class consisting of hydrogen, a lower alkyl group and a--(CH,,,,L group; Ii represents an integer of from 1 to 4 L represents a carboxy group; and formula:

L(--CH2)i1 I 2 )ll wherein L, L and L are as defined previously; L represents a carboxy group; i, j, m and n each represent integers of from 2 to 4; Z represents a group selected from the class consisting of i a I group, a phenylene group, a cyclohexylene group and a Dir- R, R, R", R R R R, R and h are as described previously; it represents an integer of from 2 to 4; and L represents represents a carboxy group;

b. a thiosulfate salt fixing agent having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine; and

c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions,

5. A blix composition of claim 2 containing in addition to (b) and (c) described therein,

d. a salt having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amirib having an ionizable proton attached to a nitrogen atom of said amine and an anion from said polyfunctional ligand described in (a).

6. A blix composition ofclaim l in which the polyfunctional ligand is ethylenediaminetetraacetic acid.

ligandis diethyleiietrinitrilopentaacetic acid.

8. A blix composition of claim 1 in which the polyfunctional ligand is l,Z-cyclohexanediaminetetraacetic acid.

9. A photographic blix composition comprising:

a. sufficient ammonium ethylenedinitrilotetraacetato ferrate (III) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter,

b. sufficient ammonium thiosulfate to produce, when dis solved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and

c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.

10. A blix composition of claim 9 containing, in addition to (a), (b) and (c), sufficient ethylenedinitrilotetraacetate tetraammonium salt to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 0.1 mole per liter and sufficient ammonium hydroxide to produce a blix solution having a pH in the range from about 5 to about 7.

11. A photographic blix composition comprising:

a. sufficient ammonium ethylenedinitrilotetraacetato cobaltate (Ill) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 moles per liter,

b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.0] mole per liter to about 5.0 moles per liter, and

c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.00l mole per liter to about 2.0 moles per liter.

12. A photographic blix composition comprising:

a. sufficient ammonium ethylenedinitrilotetraacetato cuprate (H) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about l .0 mole per liter,

b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and

c. sufficient ammonium white to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.

13. A photographic blix composition comprising:

a. sufficient tris (hydroxyethyl) ammonium ethylenedinitrilotetraaceto ferrate (ill) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter,

b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.0] mole per liter to about 5.0 moles per liter, and

c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.

14. A photographic blix composition comprising:

a. sufficient ammonium diethylenetrinitrilopentaacetato ferrate (ill) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter,

b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and

. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.

15. A composition comprising:

a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe Co and Cu, chelated by a polyfunctional ligand;

b. a salt with a cation selected from the class consisting ofan ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom of said organic amine, and with an anion from said polyfunctional ligand; and

c. a base selected from the class consisting of ammonium hydroxide and a water-soluble amine; said composition containing a sufficient amount of (a) and (b) to produce, when dissolved in water, a concentrated stock solution containing from about 0.3 mole per liter to about 2 moles per liter of (a), and from about 0.05 per liter to about 0.5 mole per liter of (b) and a sufficient amount of (c) to adjust the pH of the said concentrated stock solution in the range of from about 6.5 to about 8.5, said concentrated stock solution being added to a solution containing ammonium thiosulfate to form a solution for blixing silver in developed photographic elements.

16. A composition comprising:

a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe***, Co and Cu, chelated by a polyfunctional ligand selected from those having the formulas:

wherein L and L represent groups selected from the class consisting of a carboxy group and a P group; O and Q represent members selected from the class consisting of hydrogen, an ammonium group, a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, an alkyl group, an aryl group and a heterocyclic group; R, R R R, R, R R and R each represent a member selected from the class consisting of hydrogen, hydroxyl, an amino group, nitro, halogen, a lower alkyl group and a lower alkoxy group, such that no single carbon atom in the chain of formula I contains more than one hydroxyl group, more than one amino group and more than one nitro group; d, e,fand g each represent integers of from 1 to 4; p represents an integer of from 1 to 2; X represents a member selected from the class consisting of oxygen, sulfur, a

/Roo

\Rooo group, and a:NR group; R represents a group selected from the class consisting of an alkyl group and an aryl group; R and R represent members selected from the class consisting of hydrogen, a lower alkyl group and a -(Cl-I ),,,,-L group; It represents an integer of from I to 4; L represents a radical selected from the class consisting of a carboxy group a nitrogen atom in said amine, an alkyl group, an aryl group and a heterocyclic group; and formula:

group, a =0 and a wherein L, L and L are as defined previously; l3 represents a radical selected from the class consisting of a carboxy group group;Q and Q each represent members selected from the class consisting of hydrogen, an ammonium ion, a water-soluble organic amine having an ionizable proton on a nitrogen atom, an alkyl group, an aryl group and a heterocyclic group; i, j, m and n each represent integers of from 2 to 4; Z represents a group sele tedfrorn the class consisting and a R, R, R, R, R, R R, R and h are as described previously; k represents an integer of from 2 to 4; and L represents a group selected from the class consisting of a carboxy group and a PO group; O and Q each represent members selected from the class consisting of hydrogen, an ammonium ion, a water-soluble organic amine having an ionizable proton on a nitrogen atom, an alkyl group, an aryl group and a heterocyclic group;

b. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom of said amine and with anion from said polyfunctional ligands of formulas l and 11; and

c. a base selected from the class consisting of ammonium hydroxide and a water-soluble organic amine; said composition containing a SUfflClCl'l! amount of (a) and (b) to produce, when dissolved in water, a concentrated stock solution containing from about 0.3 mole per liter to about 2 moles per liter of (a) and from about 0.05 to about 0.5 mole per liter of (b), and a sufficient amount of (c) to adjust the pH of said concentrated stock solution in the range of from about 6.5 to about 8.5, said concentrated stock solution being added to a solution containing ammonium thiosulfate to form a solution for blixing silver in developed photographic elements.

17. A composition of claim 15 in which said cations in said salts of (a) and (b) are ammonium ions and the base of said (c) is ammonium hydroxide. X

18. A composition of claim 15 in which said metal ion in (a) is Fe''*.

19. A composition of claim 15 in which said polyfunctional ligand in (a) is ethylenediamine tetraacetic acid.

20. A composition comprising:

a. a sufficient amount of ammonium ethylenedinitrilotetraacetato ferrate (lll) to produce, when dissolved in water, a concentrated stock solution containing from about 0.3 mole per liter to about 2. moles of(a) per liter;

b. a sufficient amount of ethylenedinitrilotetraacetic acid tetra ammonium salt to produce, when dissolved in water, a concentrated stock solution containing from about 0.05 mole per liter to about 0.5 mole of(b) per liter; and

c. a sufficient amount of ammonium hydroxide to adjust the pH of said concentrated stock solution in the range of from about 6.5 to about 10.; said concentrated stock solution being added to a solution containing ammonium thiosulfate to form a solution for blixing silver in developed photographic elements.

21. In a photographic color process comprising the steps:

1. development of a light-image exposed multilayer gelatino silver halide multicolor photographic element with an aqueous alkaline primary aromatic amino color developing solution to produce a silver and a dye image, and subsequently 2. blixing the developed photographic element by contacting it with a blix solution to remove said silver image and residual silver halide in said element to leave said dye image unobstructed, the improvement comprising blixing said developed element by contacting it with an aqueous photographic blix solution comprising:

a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe***, Co**", and Cu, chelated by a polyfunctional ligand;

b. a thiosulfate fixing agent having a cation selected from the class consisting of an ammonium ion and a watersoluble organic amine having an ionizable proton attached to a nitrogen atom in said amine;

c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions.

22. In a photographic color process comprising the steps;

1. developing a light-image exposed multilayer gelatino silver halide multicolor photographic element with an aqueous alkaline primary aromatic amino color developing solution to produce a silver and a dye image, and subsequently 2. blixing the developed photographic element by contacting it with a blix solution to remove said silver image and residual silver halide in said element to leave said dye image unobstructed, the improvement comprising blixing said developed element by contacting it with an aqueous photographic blix solution comprising:

a. ammonium ethylenedinitrilotetraaeetato ferrate (Ill) at a concentration in the range of from about 0.01 mole per liter to about 1.0 mole per liter of said blix solution,

b. ammonium thiosulfate at a concentration in the range of from about 0.01 mole per liter to about 5.0 moles per liter of said blix solution,

c, ammonium sulfite at a concentration in the range of from about 0.001 mole per liter to about 1.0 mole per liter of said blix solution,

d. ethylenedinitrilotetraacetate tetraammonium salt at a concentration in the range of from about 0.001 mole per liter to about 0.1 mole per liter of said blix solution, and

e. sufficient ammonium hydroxide to adjust the pH of said blix solution in the range offrom about 5 to about 7. 

2. A photographic blix composition comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co and Cu , chelated by a polyfunctional ligand selected from those having the formulas:
 2. blixing the developed photographic element by contacting it with a blix solution to remove said silver image and residual silver halide in said element to leave said dye image unobstructed, the improvement comprising blixing said developed element by contacting it with an aqueous photographic blix solution comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co , and Cu , chelated by a polyfunctional ligand; b. a thiosulfate fixing agent having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine; c. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine and with an anion that provides a source of sulfite ions.
 2. blixing the developed photographic element by contacting it with a blix solution to remove said silver image and residual silver halide in said element to leave said dye image unobstructed, the improvement comprising blixing said developed element by contacting it with an aqueous photographic blix solution comprising: a. ammonium ethylenedinitrilotetraacetato ferrate (III) at a concentration in the range of from about 0.01 mole per liter to about 1.0 mole per liter of said blix solution, b. ammonium thiosulfate at a concentration in the range of from about 0.01 mole per liter to about 5.0 moles per liter of said blix solution, c. ammonium sulfite at a concentration in the range of from about 0.001 mole per liter to about 1.0 mole per liter of said blix solution, d. ethylenedinitrilotetraacetate tetraammonium salt at a concentration in the range of from about 0.001 mole per liter to about 0.1 mole per liter of said blix solution, and e. sufficient ammonium hydroxide to adjust the pH of said blix solution in the range of from about 5 to about
 7. 3. A photographic blix composition comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co and Cu , chelated by a polyfunctional ligand selected from those having the formulas:
 4. A photographic blix composition comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co and Cu , chelated by a polyfunctional ligand selected from those having the formulas:
 5. A blix composition of claim 2 containing in addition to (a), (b) and (c) described therein, d. a salt having a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom of said amine and an anion from said polyfunctional ligand described in (a).
 6. A blix composition of claim 1 in which the polyfunctional ligand is ethylenediaminetetraacetic acid.
 7. A blix composition of claim 1 in which the polyfunctional ligand is diethylenetrinitrilopentaacetic acid.
 8. A blix composition of claim 1 in which the polyfunctional ligand is 1,2-cyclohexanediaminetetraacetic acid.
 9. A photographic blix composition comprising: a. sufficient ammonium ethylenedinitrilotetraacetato ferrate (III) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter, b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.
 10. A blix composition of claim 9 containing, in addition to (a), (b) and (c), sufficient ethylenedinItrilotetraacetate tetraammonium salt to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 0.1 mole per liter and sufficient ammonium hydroxide to produce a blix solution having a pH in the range from about 5 to about
 7. 11. A photographic blix composition comprising: a. sufficient ammonium ethylenedinitrilotetraacetato cobaltate (III) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 moles per liter, b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.00l mole per liter to about 2.0 moles per liter.
 12. A photographic blix composition comprising: a. sufficient ammonium ethylenedinitrilotetraacetato cuprate (II) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter, b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.
 13. A photographic blix composition comprising: a. sufficient tris (hydroxyethyl) ammonium ethylenedinitrilotetraaceto ferrate (III) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter, b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.
 14. A photographic blix composition comprising: a. sufficient ammonium diethylenetrinitrilopentaacetato ferrate (III) to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 1.0 mole per liter, b. sufficient ammonium thiosulfate to produce, when dissolved in water, a solution containing from about 0.01 mole per liter to about 5.0 moles per liter, and c. sufficient ammonium sulfite to produce, when dissolved in water, a solution containing from about 0.001 mole per liter to about 2.0 moles per liter.
 15. A composition comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co and Cu , chelated by a polyfunctional ligand; b. a salt with a cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom of said organic amine, and with an anion from said polyfunctional ligand; and c. a base selected from the class consisting of ammonium hydroxide and a water-soluble amine; said composition containing a sufficient amount of (a) and (b) to produce, when dissolved in water, a concentrated stock solution containing from about 0.3 mole per liter to about 2 moles per liter of (a), and from about 0.05 per liter to about 0.5 mole per liter of (b) and a sufficient amount of (c) to adjust the pH of the said concentrated stock solution in the range of from about 6.5 to about 8.5, said concentrated stock solution being added to a solution containing ammonium thioSulfate to form a solution for blixing silver in developed photographic elements.
 16. A composition comprising: a. a bleaching agent for silver that is a salt with an unchelated cation selected from the class consisting of an ammonium ion and a water-soluble organic amine having an ionizable proton attached to a nitrogen atom in said amine, and with an anion that is a complex of a metal selected from the class consisting of Fe , Co and Cu , chelated by a polyfunctional ligand selected from those having the formulas:
 17. A composition of claim 15 in which said cations in said salts of (a) and (b) are ammonium ions and the base of said (c) is ammonium hydroxide.
 18. A composition of claim 15 in which said metal ion in (a) is Fe .
 19. A composition of claim 15 in which said polyfunctional ligand in (a) is ethylenediamine tetraacetic acid.
 20. A composition comprising: a. a sufficient amount of ammonium ethylenedinitrilotetraacetato ferrate (III) to produce, when dissolved in water, a concentrated stock solution containing from about 0.3 mole per liter to about
 2. moles of (a) per liter; b. a sufficient amount of ethylenedinitrilotetraacetic acid tetra ammonium salt to produce, when dissolved in water, a concentrated stock solution containing from about 0.05 mole per liter to about 0.5 mole of (b) per liter; and c. a sufficient amount of ammonium hydroxide to adjust the pH of said concentrated stock solution in the range of from about 6.5 to about 10.; said concentrated stock solution being added to a solution containing ammonium thiosulfate to form a solution for blixing silver in developed photographic elements.
 21. In a photographic color process comprising the steps:
 22. In a photographic color process comprising the steps: 